Steganographic typewriter



0ct. 27, 1936. D'AUVRAlN V 2,058,776

STEGANOGRAPHI C TYPEWRITER Filed July 26, 1933 3 Sheets-Sheet 3 Patented Oct. 27, 1936 UNITED s A'rEs PATENT OFFICE Application July 26, 1933, Serial No. 682,259

In Belgium August 5, 1932 9 Claims. 197-4) The" present invention relates to graphic typewriter giving simultaneously the visible impression of the type selected by the depression of a key at the board, and a second type automatically brought forward according to an arrangement of the mechanism.

Such machine is provided with a key-board having types or characters of any writing whatever or of conventional symbols; it is constituted by a mechanism constructed according to the accompanying drawings, driven by a crank handle giving simultaneously the impression of a. typewritten symbol and of that automatically brought forward. The latter has a fictitious value, and

will be used in deciphering to find the symbol for which it has been substituted.

The advancing of the fictitious symbol to the impression point is performed according to a disposition of a mechanism automatically moved by a the crank. I

After each depression of a key, the type selected to function is impressed by pulling the crank handle and simultaneously a second fictitious symbol is brought forward for impression. The

succession of these fictitious symbols constitutes the steganographic or ciphered text.

For translating it into clear text, the machine is put again in the original starting position (detailed hereafter); the keys corresponding to the 3 fictitious symbols obtained are lowered in the given succession and operation proceeds just as for producing the aforesaid steganogram.

In the drawings:

Fig. 1 is a side elevation partly in section;

3 Fig. 2 is a front view partly in section;

Fig. 3 is a planview with parts broken away;

Figs. 4, 5 and 6 illustrate separately constructional details.

With reference to these drawings, the machine 0 comprises a key-board, the keys I003 of which have as index the type which they operate, said keys being protected by a cover ring IO0I. The key levers I005 extend longitudinally throughout the machine frame and are controlled by a spring 45 I004. Each key lever is pivoted to angle plates I006, |006; the free arms of which are inturn pivoted to a connection strip I008. The angle plates I006, I006 are pivoted to transverse shafts I009, whereas the spring I004 is mounted upon a transverse rod I029. The ends of the hair-pinshaped spring extend down to a transverse T-' iron IOI0, and each connection strip I008 "has a projecting feather I035 engaged within the return spring I004. 55. The accurate position of the key. levers is sea 'steganocured by means of guiding and separating combs I049, I049. I050, I050, I05I, I05I' designate the pivots of a parallelogram allowing the key levers different movements referred to hereafter.

Underneath the key-board are pivoted a series 5 of spring-controlled detecting plates I001 pivoted to the beaded portion I052 of a transverse member "IN I, which is pivoted about a transverse spindle 2030. Underneath the key-board is also arranged a square shaft 20I6 slidably supporting 10 the combination drum 200I, the peripheral surface of which is provided with conical studs 2004 capable of moving the detecting plates I001. The shifting of the combination drum is operated by a manipulator 2001 provided with a down- 15' wardly directed feather 202I capable of engaging graduated recesses of a transverse scale member 2020 arranged at the front end of the machine.

At the left hand end of the shaft 20I6 is keyed 20 a graduated disc 300I intended for setting the start of rotation of the combination drum 200I. This disc is moved by a crank 3002 having a handle 3003. A pointer 3004 engaging the graduations of the disc 300i is fixed to the machine frame. I

At the other end of the shaft 20I6 is keyed a ratchet wheel 400i, capable of being rotated by a pawl 4008 pivoted to the crank arm 4005, which is driven by the coupling lever 4004 moved by the maindriving means of the typewriter. 40" is a control lever capable of determining the number of teeth to be engaged by the springcontrolled pawl .4000 upon the ratchet wheel 400I This lever 40" runs along a toothed quadrant I9 fixed to the machine frame.

The movements necessary for the central elements of the typewriter are transmitted from a crank handle through a friction clutch comprising male and female'cones 500I and 5002. A 40 toothed gear of large diameter 50I I transmits the movements to the central shaft I504 and meshes with a pinion I605 shown in dotted lines in Fig.

1 and in full lines in Fig. 2. The crank handle I902, I903, pivotable about a spindle I90I, is connected to a transmission rod I6, pivoted to a crank rm I3I5 of the auxiliary shaft I300, which roc the rod 4004 by means of the crank arm 50". I

In the central portion of the typewriter above 50 the key levers I005 is pivoted the clearing rocker 600I provided with lateral bearings for coupling the clearing rings 6001 and 6008. In the bearings 6002 are pivots 6003 for the support members 6004 sustaining the clearing rings 6001 and 6008. 6005 is the pivot spindle for the rocker 600I. The clearing rings 6001 and 6008 act respectively upon the abutment plates I003 and 8003 of the central 1 control discs IOI and 800i.

The bridge 60I3 constituting a support forthe rocker 600i forms part with the bridge part I20l referred to hereafter.

The clearing rocker is controlled by the arm 6025 keyed upon the shaft 6021, capable of bein rocked by arm 6026, the end of which is situated in the path of the-reciprocating crank Upon the central shaft I604 is keyed a disc IO0I provided at its periphery with a number of radial slots. equal in number to that of the key levers I005, said slots being intended for lodging abutment blades 1003. These abutment blades are pivoted to circular spindle I002 and in front'of the machine is pivoted, upon a spindle I039, a particular dog 10, capable of moving by depression one of said abutment blades I003. These handle abutment blades I003 are frictionally held in their' slots by washers IOI8. The particular dog 10 is linked by a rod I025 to the universalv bar 2 IN rocking about a transverse shaft 2I39.

Above the disc IO0I is arranged a freely rotatable disc 800I, also provided with a number of radial and vertical slots at its peripheral bead,

' said slots being in number equal to that of the key levers I005,'and in which are also lodged-a series of movable abutment blades 8003. This disc is also provided with a projecting feather 800I'. In this disc 800i, the movable abutment blades 0003 are pivoted to a circular spindle 6002 and this disc carries a type wheel 8004 having types corresponding to the key-board and intended for impression of the symbol pressedat the key-board.

The abutment blades 8003 are also frictionally pressed by washers 80I8. The upper end of the hub of said disc 800I is provided with a cup- -shaped member having an inclined rim 8050 intended to constitute a pulley groove with a similar element H50.

MM is a ring supporting-the stop dogs 9003 pivoted on a circular spindle 0002. Each stop dog' wheel H04, a fork member H05 is provided capable of lifting this type wheel and rocking about a ball pivot H06, fixed by meansof a set nut 01 to a frame portion. The pins H03 of the fork lever H05 engage a groovefof the hub H03. Thus hub is also provided at its lower ,endwith a circular cup I I50 having an inclined rim fixed to the hub portion HM and cooperating hwith the cup element 8050 to constitute, the V-shaped pulley groove at 90, in which will belodged a,

helical spring II5 I, the ends'of which are connected, so as to constitute an elasticring securing the friction required for actually rotating. the disc 800I g The lower bridge member I20I forming part of the central frame, constitutes a bearing for the central shaft I604 and also a support for the pivot spindle 6005. I202 is a bridge portion forming the other bearing for the central shaft I604 and a support for the members H05, I103 and I104 referred to hereafter. v r

. ,To the auxiliary shaft I300 is keyed a crank arm I30I having a hub I30-I'. To this crank arm I30I is pivoted a finger I302 intended for cooking the hammers I303 and operating the impact of impression. The impression hammers I303 are supported by and pivoted to spindle I304 and have extending arms I305. acted upon by the finger I302 pivoted to spindle I301.

The ink ribbon spools I402 and I402 are supported by spindles HM and NM. The two ink ribbons I430 are guided over rdllers I403, I403.

The paper tapes are moved by a driving roller pivoted to the spindle I50I, cooperating with a pressure roller I502. The paper tape is guided over a roller I502, the delivery bobbins I504 of the tape I530 being supported-upon a shaft I 503 fitted with a supporting disc I505.

I 60I is'a transmission shaft transmitting movement to the central shaft I604, by-means of the gears I602, I603, having helical teeth at 45 said shaft IBM has a pinion I605 driven by the main gear 50H.

IIOI and "02 are spring-controlled abutment knobs intended for setting, the type wheels at zero point. The knobs H03 and II04'when pushed towards the central shaft I604 will bring the abut-'- ments I'IOI, I102 in the path of the projections I150, I I5I provided in the plane of the type wheels.

The universal bar 2 IN rocking about the transverse shaft 2I39 is driven by a rocking lever 2102, the upper end of which has a spring-controlled catch 2| 03 and the lower one a connection link 2I04 pivoted to a projecting heel portion of the universal bar. 'The catch 2 I03 is pivotable about a spindle 2I05 whereas the lever 2I02 is pivoted about the spindle 2120.

The mechanism and working of the machine will be detailed hereafter under separate headings.

The key-board Towards the front side is arranged a key-board of an ordinary typewriter, the keys of which in undetermined number are distributed in vertical and horizontal rows at will.

For facilitating the present description, a machine should be considered as having42 keys staggered in two horizontal rows of ten keys and two horizontal rows of eleven keys, bearing each the symbol, the alphabetical character, the numeral or the punctuation they will put individually into action.

Each key I003 makes part with a key lever I005; the latter passes through the machine in horizontal direction from the front to the rear and forms a parallelogram movement by its uniting with the angle plates I006 and I006 and the coupling connection I008. This whole pivots upon the "main shafts I009 of fixed position and is pivoted in the points -I050, I050','I05I and I05I. The horn-shaped springs each having two arms 'l004keep the key levers in their rest position (see Fig. 2) by engagement of the studsl 035 fixed upon I008, the stud being kept wedged between said arms. e T-section iron IOI0 acts as stop point for I004. 7

Each key I003. may be depressed in the vertical direction, over-a distance required for an operation, or it may be lifted vertically, the spring I004 position when freed.

having for a function to bring it back to the rest the rod I029, which passes through the machine from one side to the other and is fixed at each end within the frame. I

Two separating combs I049 and I049 keep respective space between the levers.

The combinating drum Under the key-board is arranged the combinatthe - ing drum 200i.

This drum 2-00I is formed as a cylinder provided with a hub bored with a square hole; it moves' threaded holes are drilled in the radial direction, I intended to secure a lodging for conical studs 2004, which are placed therein at the ratio of one per generatrix upon any circumferential line whatever.

Setting the start of rotation of the drum 2001 The start of rotation of the drum may be set at any point of its circumference by'rotating the is fixed to the frame.

The quadrant setting The rotation of the drum 200I is operated by the pawl 4008, which acts upon the ratchet wheel 400I fixed upon the square shaft 2M6 and the number of teeth of which is selected at will for determining the number of generatrices upon the combinating drum 200 I.

The crank arm 4005 is driven from the crank handle I902 by means of the connection rods 5006 and 4004; it supports the pawl 4008 and moves it in its circular reciprocating movement about the axis of the square shaft 20I6.

The stroke of the crank 4005is always of. the same amplitude and may be determined for an angle comprising a number of teeth of the pawl wheel Mill. The shutter lever 40I1 is intended for being inserted between the pawl 4008-and the ratchet wheel 400I and according to the stopping point which it occupies along the toothed quadrant 40I9, it will prevent the engagement of the ratchet wheel 40! by the pawl 4008 for one, two, three or X teeth.

The friction clutch The clutch element 5002 fixed to the crank handle I902 frictionally moves the element 500I fixed upon the large gear 50. The whole is mounted'upon the shaft II which acts as rotation pivot for this clutch.

The clearing action The'elements necessary for'this action are num- Each bearing 6002 forms the seat for a pivot 6003 fixed in the arm 6004-, both arms 6004 supporting a ring of I-section, the two flanges of which constitute the clearingrings 6001 and 6008 arranged coaxially with the central shaft I604.

' The rings 6001 and 6008 are lodged between the uprights of the bridge I20I'. which act as vertical guides. In the inner free space of these rings 6001' and 6008 are mounted the discs WM and 800I, so that only the horizontal portions of the abutments 1003 and 8003 are overhead the inner part of the flange of the rings 6001 and 6008.

The clearing rocker 600I rocking upon its shaft 6005 only makes a reciprocating movement upwards with back motion downwards, according to the operation of the lever 6025, with strokes the amplitude of which is determined by the shifting which is necessary for bringing the abutments 1003 and 8003 to their rest position, and the back movement downwards to put the rocker 600I and this complete machine part 6000 out of any reach of the rotary central portion which will be considered hereafter.

The rotary central portion The rotary central portion of the machine is a whole of constructional elements to be detailed hereafter and rotating all around the axis of the central shaft I604 upon which they are mounted. Disc with movable abutments The disc I fixed by.its hub upon the shaft I 604 supports at its periphery a bead of circular shape cut by 42 radial and vertical notches' at equal distances the-one from the other. In the 42 notches are lodged 42 movable abutments 1003 engaged upon the circular pivot spindle 1002. The abutments 1003are made of sheet metal of about 1%; m/m thickness; they have the shape of an angle plate, the angle of which'determines the center of pivotment and is provided for'this purpose with a hole through which passes the pivot 1002.

One of the anns of 1003 is vertical and is turned towards the center of the disc 100I with respect to its center of pivotment and projects from the bead at its upper portion; the horizontal arm of 1003 passing underneath the center of pivotment of 1002 projects out of the periphery of the disc 100I, so as to extend over the flange of the clearing ring 6001. The part of the angle plate 1093 projecting horizontally out of the disc 100I is bent at 90 for presenting more surface within the horizontal plane. Each blade 1003 is accompanied in its lodging by a slotted pressure washer 1MB affording the required resiliency for maintaining an abutment 1003 by friction against the wall of the notch, so as to hold said abutment in any position to which it has been intentionally brought.

Second disc with movable abutments This machine part comprises the following elements: 800i, 800I', 8002, 8003, 8004, 80I8, 8050.

The disc 800I is integral with MM, 8004, I and 8050; it freely rotates upon the shaft I804 and is provided at its periphery with a bead of circular. section provided with a series of. 42 radial and vertical notches at equal distances the one from the other.

In the 42 notches of the bead are lodged 42 movable abutments 8003 accompanied bya slit pressure washer 80I8 and engaged upon the circular pivot spindle-8002. 1

' 9003 and 9020.

determines the center of pivotment and which is provided with a hole for engagement of the pivot spindle 0002. One of the arms of 0003 is 'vertically directed and is turned outwardly from the center of \the disc 300I with respect to its pivotment center and projects from the head of 800I at its lower portion. The horizontal arm of 8003 starts from the center of pivotment, a portion of the arm bent at 90 being over the flange of the clearing ring 0000.

,000I' is an abutment feather, formed at the upper face of the disc 000I; it extends from the center of the shaft I004 so as to come over the part of the dogs 9003 projecting inwardly of the stopping" ring 000I. ;300I is intended for stopping the rotation of the disc 000I when it meets with is stopping dog 9003- whi'ch, by depression of a key at the board, is brought to position A and issituated in the plane of rotation ofthe feather 000i corresponding to the symbols of the key-board of the machine. Each key causing by depression the meeting of 9003 with 000i will stop, at the point of impression in front of the hammer I303,

the type of the wheel 8004 corresponding to the key acted upon. The hub of the disc 800i sup-' ports at the end of its upper portion a circular -dish 8050 with a rim inclined at 45 with respect to the bottom of the dish; it makes part with the hub and acts as driving pulley for rotation of the type wheels at the moment specified hereafter.

The ring and the stopping dogs This part comprises the elements 000I,

MM is aring to which are fixed the bridges I20I and,I202; the central part of the ring leaves a free circular space for the reception of the rotary part of the machine mounted on the central shaft I000 under the conditions required for .the different movements. p

concentrically to the shaft I604, the stopping ring 900I has a vertical. wall provided with a series of 42 radial and vertical'slits which con-"- stitute guides for the stopping dogs 3003.

At a distance farther apart from the center of I604, a second series 0142 notches constitute a lodging for the stopping dogs 9003. Thisseries of notches is arranged in a circular concentric bead forming'part of the ring 900I. In the center of this bead passes the circular spindle 0002,- which constitutes a pivot for the stopping dogs 0003/The latter are distributed with their longicenter of I004 andare spaced apartat .equal tudinal axes along the radii starting from the distances from each other. The connection rods 9020 individually transmit to the stopping dogs 9003 the movements imparted by the diflerent key levers I005 from the position Otowards A 'with back motion to O, or from 0 towards B,

with back motion to 0, see Fig. 1, according to the depression of a key I003 at the board or the by one single key lever I005 dividual connection 0020.

Barrel with. fictitious types This part comprises the elementsIIlI, 02,

II, H00, H05, H00, H01, H00 and H50.

. The disc I IN withhub is keyed upon the shaft I 003 and rotates therewith. At a certain distance from this axis and according to a concentric by m or the inclrcle, 42 holes are bored at equal distances apart and at right angles to the plane of the circle I I02 wedged in the plate I I03 to connect the plate and the disc together. .The. symmetry of the this succession is determined by the connection of said dogs to the key levers I005.

The lever 05 isvforked, the two arins being provided at their ends with pins 03 which engage within the circumferential groove provided iii thebody of the hub of H03. This fork rocking upon the'ball pivot 00, which is fixed after adJustment in height by means of a nut I I01, has no other function than to lift the plate .03 with the barrel '04 for adjusting same with respect tothe disc IIIII. V

.II" is 'a circular cup with flat bottom, the edges of which are inclined at 45 with respect to its bottom; it is fixed at the lower portion of the hub of disc M with its edge turned upwards. The edge 0 I- I 50 form a pulley with a right-angled groove between them, in which is lodged a helical spring IIBI which, having its ends connected, completely embraces the periphery of the groove, and by its tension secures the friction required to make IO0I revolve under the rotation of I I03 in certain cases as will be seen hereafter. a

The bridges of the central frame This machinepart comprises the elements I20I and I202. I20I is an element having the'shape oi a'suspension bridge, the horizontal apron of which is connected at thebottom by two vertical columns to a' ring occupying the upper plane. This ring .is carried by means of a circular flange in .the

'they act as guides- The apron of this bridge constitutes the base of the central portion, extends horizontally in the direction 'of the diameter of the ring of the bridge from then-ont to the rear, and is bored in its center vertically for the reception oLthe central Shaft mg which\takes seat n this bore.

Towards the front and at a distance determined by-the radii of-the gears I602 andv I603, is provided a second bore at right angles to the foregoing for lodging the shaft I60I which rotates I therein about its axis.

vided an opening for the free movement of the This section The element I202 is similar to that 'I20I. It is also fixed to the ring of the stops 000i by engagement therewith and screws. and the latter constitutes the base of the bridge I202, the apron of which is at the upper portion and horizontal in the direction of a diametrical line and at right angles to the position of HM.

At the rear of the apron and in the same plane is adjusted, at right angles thereto, another apron supported by a third pillar which takes seat upon the ring and to which is suspended the lever 05.

In the center of the apron I202 is provided a bore for engagement of the shaft I604.

In the vertical pillar of the bridge I202 is prolever II05, the pivotI I06 01' which is fixed in the apron.

In they left hand vertical pillar of the bridge I202 (see Fig. 2) are mounted the knobs I103 and I104 to be examined hereafter.

Auxiliary movements and impression hammers comprises the elements I300, I30l', I302, I303, I304, I305 and I301.

The whole of these elements constitutes a movement intended to actuate the hammers I303 sev curing the impact for impression of the types.

inking This machine portion comprises the elements Mill, Hill, I402, I402, I403, I403 and I430.

This mechanism cooperates to the regular shifting of the ink ribbon in order to keep the hiking clean.

Feeding of the impression paper This section comprises the elements I50I, I 502, I502, I503, I500, I505 and I530.

The visible impression of the types is simultaneously made upon two tapes of paper shifted according to the impact of the elements which secure the automatic progression after each record. The whole-of the elements of which the numerals are cited secure this movement.

Transmission of the movement of the crank handle to the central shaft This section comprises the elements: IOI I002, I003,'I000, I005 The pinion I005 is keyed upon the transmission shaft I00i, rotates therewith and is driven by the main gear 50, which transmits the movements of the crank handle I902.

The movements imparted to the pinion I005 are transmitted by the the central shaft I000 I002 keyed upon I00l is a toothed wheel with helical teeth which meshes with a similar gear I003, the axes of the two gears being at right angles to each other.

This gear I003 is keyed upon the central shaft gears I002 and I003 to I000 and controls its rotation about their common axis. 4 V

' Settiny the machine in starting, position towards the center of'the machine by the operator. This abutting makes the barrel I lll lstop in its revolution, so as to make it present always a determined point of the periphery of H04, in front of one of the impression hammers I303 and to cause the impression of. a type which shall always be the same.

The stud i150 fixed upon the wheel 8004 rotates with-it about the center of the central shaft I504, passes freely in front of the spring-controlled abutment I102 during the working of the machine; like the stud I15I, the stud I150 only abuts with the spring-controlled abutment I102 -when the operator has shifted it towards the center of the machine by pressing the knob I104 by means of a finger of his left hand. This abutting makes the wheel I104 stop at a point determined upon its periphery which always brings the same type as the impression point in front of the hammers I303.

Universal bar This section comprises the elements 2IOI, 2I02, 2I03, 2l04, 2105, M29 and 2I39.

The universal bar 2 I III is in the shape of a blade sustained by three arms fixed to the shaft 2I30, which pivots about its axis in bearings provided in the frame of the machine and mounted at the rear of the detecting blades I001 and slightly lower than the abutment heel of the latter, so that they may come into position over said heel when they are brought backwards in position A under the action of the studs of the combination drum 200I.

Running in horizontal line under the key:

board, the universal bar extends somewhat beyond the latter on either side, in order to secure its function upon all the key levers which it will have to operate according to the control given by the detectors I001 obeying the conical studs .In its reciprocating movement, the crank I902 makesthe lever 2I02 oscillate by means of. 2I03 which it strikes during its backward movement, 2I02 oscillating upon 2i 29 pulls the connection 2I0 I which drives the universal bar 2IOI and 2 makes it oscillate about 2| 33.

This strike of the crank I902 against 2I03 lifts the universal bar 2IOI and simultaneously the conn ction 1025 linked in the arm of 2IOI and actuated by the latter.

In its ascending movement, the universal bar 2IOI lifts the connection 1025 which by making .the special dog M oscillate. rocks an abutment I003 from the ring of movable abutment plates 100I; simultaneously, the bar 2IOI strikes the abutmentheel of the detector I001 which extends over same, and rocks an abutment 0003 from'the ring of movable, abutments 000i by means of the dog 0003 which it causes to oscillate from O to B by lifting the lever I005 and the connection 9020 under which the lifted detector I001 is positioned. w

The crank handle I002 moves backwards until the moment when 2i 03 escapes from it; then the universal bar falls back to its rest position with all its connected parts, as it, may be seen in the drawings, Fig. 1, and the crank I002 then continues its stroke towards the rear until its rest position, shown in the drawings, Fig. 1.

Working of the machine.--Preparation of the starting point Before any transcription with the machine, it is indispensable to put, the difierent elements in a determined position in order to secure the reference points which in their 'whole constitute the key or starting point.

For this purpose:

(1) The starting of rotation of the combinating drum 200I is determined by rotating the handle 3002 for presenting the required graduaaccording to the number of teeth to be taken by the pawl 0000 upon the ratchet wheel M.

trolled abutment 40 there.

- tions.

, (4) The lever arm 0020 isfiiulled forward to lift. the clearing rings 0001 and,6000 and put all the abutments 1003 and 8003 in their neutral posi- 'S;etti1w the start To start the transcription of a clear text into a ciphe'red text, after having set the machine to the different aforesaid positions, the type wheels 0000 and H have to be brought in the starting position; for this, by means of the middlefinger of the left hand. the knob I100 is pushed towards the center of the machine; it is kept so while, by means of the right hand, the crank handle I002 is pulled forward; this causes the rotation of the shaft N00,; with :the type-wheels and the discs with movable abutments.

Under the friction of the spring II5I in the groove formed by the cups I150 and 0050, this rotation is transmitted to the disc 0000 which brings the stud- I150 against the spring-con- I102 and stops its rotation At this moment, the spring 50 slips and allows the type wheel H00 and disc "II to revolve separately with the shaft'l000.

By means of the fore-finger of the left hand,

.the knob I103 is then pushed inwardly to makev the abutment II project towards the center' and against which the stud -I10I will strike. This will stop the rotation of thesections IIOI, I003,

shutter lever 00".

100I, the large gear 50 and the clutch cone 500I, which the handle I002 had brought in rotation by friction. r

Continuing its forward stroke, the handle I 002, by means of therconnected parts and of the mechanism, throws. in the hammers I303 which imprem the types which the wheels 0000 and I I00 have kept in front of the impression point after stopping. Arriving at the end. of its forward stroke, the handle I002. causes the lifting of the section 600I- by abutting the arm 0026, which oscillates about'6021 the am 0025 enga ing 000I.

During its forward stroke, the handle 10" position, then the movable catch 2l00,.to actuate the universal bar 21"" whichwill lift the detector I001 and the key. lever I000 x.

- notches.

By means of the connection 0020, the key lever dog 0003 from 0 to B, which in turn will press upon the part bent at 90 of the movable abutment 0003 held at this moment in frontof it.

Said abutment 8003 by turning about the axis of the circular pivot 0002 will incline its vertical arm and move its end towards the center. It is kept in this position and it can be designated as brought in function or cooked;

Simultaneously with'the key lever I005 the universal bar 2IOI makes 'the special dog 10I0 oscillate by lifting the connection 1025 and puts also in function the movable abutment 1003 which is in front of the dog 10.

At the moment when the handle I002 allows the escape of the movable catch 2 I03, while continuing its stroke towards the rear, the freed universal bar 2IOI drops downwards and allows the dogs 10 and 0003 acted upon to return in their neutral positionsuch as they may be seen in the drawinga'Fig. 1.

.When the handle I002 arrives at the end of its rear stroke, the operator frees the knobs I103 and I100 which he has kept pushed inwards during the forward and rear strokes of the handle I002.

At'this moment, a movable abutment 8003 is cocked upon the disc MM and a movable abutment1003 is cocked upon the disc 100 I; the latter are kept cocked by the pressure exerted upon the walls of their lodging by.the slotted washers 10I0 and 80I0 which are associated therewith in their This represents the machine at the moment for starting the transcription of the clear text in ciphered.

Working of the machine For this purpose, the first type to be written is depressed at the key-board with one finger of the left hand. This depression lowers the key lever I000 which pulls upon its individual connection 0020 and upon the stop dog 0003 corresponding thereto; the latter by oscillating from 0 to A uponthe pivot 0002 brings its free part inside the ring 000I within the plane of rotation of 000I'.

At this moment the crank handle I002 is pulled forward; the latter makes the central shaft I000 rotate which by revolving drives the discs 100I and HM and also disc 000I by friction of the spring IISI. Said disc 000i will rotate until the moment when the feather 800I will strike the dog 0003 of' the key which the operator keeps within the plane of revolution. The discs "M and M will continue their revolution until the abutment 1003 which has been c'ocked upon the disc 100i by setting the start ofthe' foregoing operation, will strike the abutment 0003 alsococked upon the disc 000I. These two abutments will strike each other,-because the vertical arm of each is in the path of revolution of the other owing to the inclination which is imparted to them by putting them into operative P sition.

The whole central rotary portion of the machine stops here its revolution and at this mo- -ment the female cone 5002 of the friction clutch slips upon 500I and allows the handle I002 to continue its forward stroke for causing. the oper-- tion of the hammers I303 and securing mermpression of the types presented by the wheels 0000 and 00 at the spot of impression.

After having performed the impression of the types, the handle I002. strikes the lever .0020, while continuing its forward stroke and provokes the movement of the clearing section 8003 in their neutral position just at the moment when the handle I902 arrives at the end of its forward stroke, just like at setting at starting position; at the backward movement, the handle I902 first frees the lever 6026, which allows the clearing elements 600I/ 6008 to drop down to their neutral position. Then it engages the catch 2 I03, which controls the universal bar 2IOI for the cocking of an abutment I003 and for the cocking of an abutment 8003 by one of the stop dogs 9003 put in action by another conical stud 2004 of the drum 200IL After cocking the movable abutments I003 and 8003 the handle I902 is brought to its neutral position and the operator frees the key which he has kept depressed and which represents the first type of the text to be written.

When the operator has brought the handle I902 to its neutral point, he may immediately depress at the key-board the second type of the clear text to be written, then pull the handle I902 as herebefore, bring it back to itsstarting point and then free the key at the board at the last moment. For each type hewill in the same manner up to the end of the text.

Under these conditions, the types presented for impression by the wheel 0000 will correspond to those selected at the keyboard and a fictitious text will be impressed by the wheel H00.

Example For the following words depressed at the key-- board; CRYPTOGRAPHE SCYTAL presented by 0000, the wheel H will perhaps present: AKRI'I'IZAMZIZ KKRAMI; this depends upon the diiierent settings and upon the relation selected between the key-board and the distribution of the stop 900i.

I claim: 1. A steganographic typewriting machine of dogs 9003 in the ring of stops the hammer-impression type, comprising a frame,

a key-board, key levers capable of being shifted downwards and upwards, a central vertical shaft, two type wheels on said shaft and adapted to be rotated thereby, one of the type wheels being capable of variable angular movement with respect to the other for simultaneously producing a visible impression in clear writing and a ciphered impression, two independent discs mounted on said central shaft and rotatable about the axis thereof, series of movable abutments on said discs, said abutments allowing the free rotation of each disc, but capable of being moved to be in the path of rotation of each other, so'as to cause the mtation of one disc by the other, each disc being integral with one type wheel, an oscillating universal bar, a dog controlled by said universal bar to move an abutment of one disc, a combination drum, means moved by said drum so as to become engaged by the universal bar'for the pur--v pose of shifting a key lever upwards, a dog controlled by said upwardly moving key lever to move an abutment of the second disc, a stop dog controlled by the .key lever depressed at the keyboard, a projection on the disc associated with the ype wheel for clear impression, and driving means for imparting the various movements to the elements. f

2. In a steganographlc typewriter of the type set forth, a combination drum formed with a cylindrical body shiftable along a square shaft d rotated thereby, said shaft being arranged transversely underneath the key-board, conical studs arranged upon the peripheral surface of the drum, oscillating detecting plates operated by said studs, and an, oscillating universal bar studs arranged upon the peripheral surface of the drum, said studs being arranged at the intersection of a number of equidistant generatrices and a series of peripheral circular lines corresponding to the axes of a number of adjacent key levers, a ratchet wheel at the end of the square shaft, said ratchet wheel having a number of teeth corresponding to the number of generatrices on the drum, a pawl for rotating the ratchet wheel, oscillating detecting plates operated by said studs and an oscillating universal bar en gaging said detecting plates.

4. In a steganographic typewriter of the type set forth, a. combination drum formed with a cylindrical body shiftable along a square shaft and rotated thereby, said shaft being arranged transversely underneath the key-board, conical studs arranged upon the peripheral surfacev of the drum, said studs being arranged at the intersection of a number of equidistant generatrices and a series of peripheral circular lines corresponding to the axes of a number of adjacent key levers, a ratchet wheel at the end of the square shaft, said ratchet wheel having a number of teeth corresponding to the number of generatrices on the drum, a pawl for rotating the ratchet wheel, oscillating detecting plates operated by said studs, an oscillating universal bar engaging said detecting plates, and means for setting the starting point of rotation for the square shaft. 7

5. In a steganographic typewriter of the type set forth, a combination drum formed with a cylindrical body shiftable along a square shaft and rotated thereby, said shaft being arranged transversely underneath the key-board, conical studs arranged upon the peripheral surface of the drum, said studs being arranged at the intersection of a number of equidistant generatrices and a series of peripheral circular lines corresponding to the axes of a number of adjacent key levers, a ratchet wheel at the end of the square shaft, said ratchet wheel having a number of teeth corresponding to the number of generatrices on the drum, a pawl for rotating the ratchet wheel, oscillating detecting plates operated by said studs, an oscillating universal bar engaging said detecting plates, means for set- 1 ting the starting point of rotation for the square shaft, and means for putting a number of teeth of the ratchet wheel out of operation.

6. In a steganographic typewriter of the type a described, a frame, a central shaft, a pair of type wheels on said shaft, a pair of discs on said shaft associated with said type wheels and arranged to rotate the type wheels, movable abutments on said discs for controlling such rotations,

and a clearing rocker pivoted Within the frame for moving said abutments in their non-operative position, said rocker comprising a ring of I-section, coaxial with said shaft and the flanges of which act on the abutments, guide ways for the ring, a rocking plate and. a lever acting on said plate.

7. In a'steganographic' typewriter of the type described, a central shaft, a pair of type wheels, a pair of discs controlling the angular position of the type wheels, sald' discs having a peripheral I bead,.equidistant radial and vertical slots in said head, rocking abutments lodged in said slots, said 'abutments being in the shape of angular plates pivoted at their apex to a common circular shaft, and washers 'frictionally holding said abutments in their different positions.

8. In a steganographic typewriter of the type described, a frame, a central shaft, a pair of type wheels on said shaft, a projection on said type wheels, apair of spring-controlled abutment knobs mounted in the frame and capable of each engaging a projection for the purpose of setr ting the type wheels in a starting position.

9. In a steganographic typewriter of the type described, a frame, a transverse universal bar rocking about a transverse shaftand having a projecting heel portion, a lever pivoted to the frame, a pivoted strip connecting the projecting heel of the universal bar to one end of said lever, and a, reciprocating crank handle, the free end of said lever being in the path of said reciprocating handle.

FERNAND DAUVRAIN. 

